Pressure-induced lead-free halide double perovskite [formula omitted] for optoelectronic applications

Abstract

The structural, electronic, optical, mechanical and thermodynamic properties of the lead free double perovskites Rb2CuSbX6(X=Cl,Br) were investigated using first principles based on density functional theory (DFT) under pressure. Our calculated results are in good agreement with other experimental results. Electronic and optical features are pressure dependent, including dielectric effect, pressure-dependent refractive index changes, strong UV reflectivity, suggesting potential applications in solar heating reduction. Using the Voigt-Reuss-Hill approximation, an increase in stiffness, of Rb2CuSbX6(X=Cl,Br) is observed with increasing loads, revealing its stability, making it appropriate for shaping. By analyzing the formation energy and Born's stability criteria, we justified the stability to check the mechanical and thermodynamic stability of the material. In addition, the mechanical properties of Rb2CuSbX6(X=Cl,Br) conducted with the study of elastic constants, elastic moduli, machinibility index, Kleinmen parameter and Vickers hardness. Our investigation indicates that both the materials provide significant potential for very high-quality optical data using optoelectronic applications.